Topical antimicrobials are currently prescribed by healthcare providers to prevent and treat a variety of serious skin infections such as impetigo, infected diabetic ulcers, venous stasis ulcers, infected surgical wounds, burns, acne, psoriasis and other topical infections. Increasingly, topical antimicrobials that contain antibiotics are not effective against microbes which have developed drug resistance (i.e., antibiotic-resistant microbes).
Drug resistance is usually caused by a mutation within the microbe. When a colony of microbes is subjected to a dose of an antimicrobial, most of the bacteria die. However, occasionally some microbes, by chance, harbor mutant genes that render them resistant to the antimicrobial drug. Not only do these bacteria survive the antimicrobial treatment, but they transfer their “drug resistant” genes to their progeny (one bacterium can leave approximately 17,000,000 offspring within 24 hours). As a result, a specific antibiotic or antimicrobial used to treat an infection caused by that microbe may no longer be effective. Furthermore, once a microbe develops resistance to a specific antimicrobial, there is the possibility that the microbe will concomitantly be resistant to the entire class of antimicrobials.
Certain antimicrobials, especially antibiotics, are becoming increasingly ineffective due to the rapid increase in drug-resistant forms of microbes. For example, mupirocin ointment (Bactroban®, SmithKline Beecham) is a topical antimicrobial used most frequently for treatment of impetigo. Mupirocin has been shown to be highly effective against Staphylococcus aureus, S. epidermidis, S. saprophyticus, and Streptococcus pyogenes. Unfortunately, microbes frequently develop drug resistance to mupirocin.
What is needed are pharmaceutical compositions useful in the prevention and treatment of infections and diseases which comprise an antimicrobial agent and one or more medicinal agents and which remain antimicrobially active in an aqueous environment, and more specifically an aqueous environment that contains sodium chloride.